In the related art, a display element provided in a display device includes an electro-optical element with the brightness being controlled by an applied voltage and an electro-optical element with the brightness being controlled by a flowing current. A representative electro-optical element with the brightness being controlled by the applied voltage includes a liquid crystal display element. On the other hand, a representative electro-optical element with the brightness being controlled by the flowing current includes an organic Electro Luminescence (EL) element. The organic EL element is also called an Organic Light-Emitting Diode (OLED). An organic EL display device using an organic EL element that is a self-emitting electro-optical element can easily realize various features such as thinning, low power consumption, and high luminance, as compared to a liquid crystal display device requiring a backlight, a color filter and the like. Therefore, in recent years, active development of organic EL display devices are under progress.
As a scheme for driving the organic EL display device, passive matrix schemes (also called “simple matrix schemes”) and active matrix schemes are known. An organic EL display device employing the passive matrix scheme, which is simple in structure, is difficult to achieve an increase in size and high definition. On the other hand, an organic EL display device employing the active matrix scheme (hereinafter, referred to as “active-matrix organic EL display device”) can easily realize an increase in size and high definition, as compared to the organic EL display device employing the passive matrix scheme.
In the active-matrix organic EL display device, a plurality of pixel circuits are formed in a matrix. The pixel circuit of the active-matrix organic EL display device typically includes an input transistor configured to select a pixel and a drive transistor configured to control supply of a current to the organic EL element. Note that current flowing from the drive transistor to the organic EL element may be hereinafter called “drive current”.
In the active-matrix display device, a plurality of data lines (also called “source lines”), a plurality of scanning signal lines (also called “gate lines”) intersecting the plurality of data lines, and a plurality of pixel circuits arrayed in matrix along the plurality of data lines and the plurality of scanning signal lines are formed in a display unit. To cope with higher definition of a display image, a Source Shared Driving (SSD) scheme for driving more data lines while suppressing an increase in drive circuits is employed in some such active-matrix display devices. Here, the SSD scheme is a scheme in which the plurality of data lines in the display unit are grouped into a plurality of sets of data line groups where one set is formed of a predetermined number (two or more) of data lines, and an analog video signal is applied in time division manner to the predetermined number of data lines in each set.
When the SSD scheme is employed in the active-matrix display device, an analog video signal is applied to each data line via a switched-on analog switch, and a level of a control signal of the analog switch is then changed so that the analog switch is switched off, as a result of which voltage of the analog video signal is held in the data line. While the voltage of the analog video signal is thus held in each data line, any one of the plurality of scanning signal lines is activated (selected), and the voltage of the data line is thereby written, as pixel data, into the pixel circuit connected to the activated scanning signal line.
Note that the active-matrix organic EL display device employing the SSD scheme is disclosed, for example, in PTL 1. In this organic EL display device, a color display is performed based on a RGB tri-color. At that time, data lines in a display panel are grouped into a plurality of sets where one set is formed of three data lines including an R data line that is a data line to which a pixel circuit corresponding to a red pixel is connected, a G data line that is a data line to which a pixel circuit corresponding to a green pixel is connected, and a B data line that is a data line to which a pixel circuit corresponding to a blue pixel is connected, and one demultiplexer is arranged for each set. Each demultiplexer is configured to receive a data signal output from a data driver (data line drive circuit), and apply the data signal in time division manner to the R data line, the G data line, and the B data line connected to the demultiplexer.